Sensor separation apparatus and method

ABSTRACT

A separation apparatus, comprising an identifier arranged to identify the particles in a group of particles that have a specific property, an affinity modifier arranged to modify an affinity of the identified particles relative to that affinity of non-identified particles in an group, and a separator arranged to separate the particles in the group based on their difference in the affinity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is the U.S. National Stage of PCT/NL2015/050841, filed Dec. 4,2015, which in turn claims priority to Netherlands Application No.2013925, filed Dec. 5, 2014, the entire contents of both applicationsbeing incorporated herein by reference in their entireties.

The invention generally relates to separation of particles, inparticular in recycling.

Separation apparatus are known in the prior art and they are typicallyused in raw materials processing for the classification of mixed streamsof particles of recycling material into streams with particles ofdifferent types of material. The known sensor separation apparatuscomprises an identifier, in particular a sensor that analyses a group ofparticles in order to assess the type of each individual particle. Afterthe particles of the relevant type have been identified by the sensor, aseparator is activated that physically separates the identifiedparticles from the group of particles, for example a series of nozzlesis actuated so that they initiate jets of air that eject the identifiedparticles from the stream such that they are separated from the group ofparticles.

A disadvantage of the sensor separation apparatus known in the art isthat they are not very accurate. In particular, the air jets willaccidentally hit and eject not just the identified particles, but alsoneighboring non-identified particles which may be of a different type.Especially, when the particles are closely arranged in the group thisdecreases the accuracy of the known sensor separation apparatus. Asolution in the art is to arrange the particles very sparsely in thegroup to avoid accidentally hitting and ejecting neighboring particlesby the jet of air. However, this lowers the capacity and affects theeconomy of the process. For example, economic recycling of a mixedstream of smaller particles of physically similar or identicalparticles, e.g. shredded particles of a plastic material, e.g. PET orPE, having different colors and a maximum dimension of several mm, e.g.10 mm or less.

EP2343136B1 discloses a separation method intended to extract a target,using viscosity of a liquid, from a separation subject in which thetarget and a non-target are mixed. The disclosed method comprisesdistinguishing the target from the non-target; obtaining positionalinformation of the target distinguished in the distinguishing, attachinga liquid to the target based on the positional information andextracting the target from the separation subject by bringing a catchmember into contact with the separation subject such that viscosity ofthe liquid causes the target to adhere to the catch member. In order tolet the viscosity of the liquid cause the target to adhere to the catchmember, an amount of the liquid attached to the target, the viscosity ofthe liquid, a thickness of the target, an area of the target, anddensity of the target need to satisfy multiple expressions. A stainlesssteel plate a silicon rubber plate or a woven wire made of stainlesssteel are proposed as catch member. The length of time for which thecatch member was placed on the separation subject is in the order ofthree seconds. This is a relatively long time. Also sufficient pressureis to be exerted by the catch member in order to enable that viscosityof the liquid causes the target to adhere to the catch member.

The invention aims at alleviating one or more of the aforementioneddisadvantages. In particular, the invention aims to provide a sensorseparation apparatus with improved accuracy and efficiency. To that end,the invention provides for a separation apparatus, comprising anidentifier arranged to identify the particles in a group of particlesthat have a specific property, an affinity modifier arranged to modifyan affinity of the identified particles relative to that affinity ofnon-identified particles in the group, and a separator arranged toseparate the particles in the group based on their difference in theaffinity.

By providing the separation apparatus with an affinity modifier, it maybe achieved that only the identified particles that are, e.g.commercially relevant, may be separated from the group based on aprovided difference in the affinity without disturbing neighboringnon-identified particles. This way, accidentally separating anon-identified particle may be counteracted, and thus the accuracy ofseparation may be increased. Further, the affinity of the particle maybe, e.g. the tendency of the particles to affix onto the separator, and,preferably, the affinity modifier increases this tendency. For example,the affinity modifier may be arranged to modify the force of attractionor attachment force of the identified particles relative to that forceof attraction or attachment force of non-identified particles in thegroup, such that identified particles may be attracted onto theseparator. The tendency may be increased by means known in the art, forexample, increasing the adhesiveness of the particles, but also bystatically charging the particles or using magnetization.

It is noted that the affinity modifier is arranged to modify theaffinity of the identified particles relative to that affinity of nonidentified particles. This may e.g. comprise the following foursituations: (1) the identifier identifies particles that arecommercially relevant and the affinity modifier may then be arranged tochange the affinity of the identified particles such that a separatorcan separate the identified particles from the group, e.g. by picking orengaging the particles, or (2) the identifier identifies particles thatare commercially relevant and the affinity may then be arranged tochange the affinity of the non-identified particles such that theseparator can separate the non-identified particles from the group, or(3) the identifier identifies particles that are not commerciallyrelevant. The affinity modifier may then be arranged to change theaffinity of the non-identified particles such that the separator canseparate the non-identified particles from the group, or (4) theidentifier identifies particles that are not commercially relevant andthe affinity modifier may then be arranged to modify the affinity of theidentified non-commercially relevant particles such that the separatorcan separate the identified non-commercially relevant particles from thegroup. It is noted that the identifier selectively and individuallyengages the particles, i.e. each particle of the group is being engagedand identified by the identifier.

By providing the separation apparatus with a separator, it may beachieved that, e.g. the identified particles with a modified affinitymay be selectively separated from the group, and the non-identifiedparticles may remain undisturbed. Consequently, the particles may thenbe arranged more closely together, and thus increasing the capacity andthe economy of the process. As an option, it is noted that once theseparator has separated the identified particles from the group, asecond separator or more separators arranged in one go may additionallybe included to separate remaining particles of a different type ofmaterial, color, or size, and thus more than one type of particle may beseparated from a single sorter system.

The particles in the group may be small particles of, e.g. plastic,metal and/or wood, with a diameter that may range between 1-20 mm.

The identifier may identify the particles in the group on the basis of aspecific property, e.g. material type, weight, color, shape and/or size.Specifically, non-physical property, e.g. same density but differentcolor, or size out of a specified range. For example, a particle of thegroup may be identified with the specific property of color whileanother particle of the group may be identified with the specificproperty of size. It is noted that the identifier may be arranged toidentify multiple specific properties, however, it is also possible tohave multiple identifiers aligned in a row, each identifier arrange toidentify at least one specific property.

The separation apparatus may further comprise a layerizer arranged tobring the group of particles in layer. This way, a planar array ofparticles may be provided, e.g. a curtain or a bed, so thatidentification can be facilitated and the particles may be provided witha known spatial relation. This way, it may also be prevented that toomany particles stick onto each other and/or avoiding that, e.g. two ormore particles are overlapping each other such that the identifier isunable to identify the lower particles.

The group of particles may be brought in a layer arrangement and/or bedby, for example, forcing the group of particles through a channel,sieve, groove, slit, slot or by means of a sweeper. Further, it is notedthat the layerizer may also comprise a jig causing a pulsation such thatthe particles may be in a layer arrangement and/or bed and thus theidentifier can easily identify at least one specific property of theparticles.

Preferably, the layerizer provides the particles in the layer with aknown, preferably constant, spatial relation, e.g. using a belt conveyorwith compartmentalized belt surface, or a belt surface withpre-impressed spatially arranged electrostatic charges that temporarilyfixate singular received particles until they reach the separator in thelayer between the identifier and the affinity modifier. By doing so, theaccuracy of the affinity modifier may be further increased, andaccidentally modifying an affinity of the non-identified particles maybe prevented.

The layerizer may comprise a conveyor belt surface on which theparticles are deposited in a planar layer. The particles may, forexample be in a top layer wherein the particles are non-overlapping, orin a monolayer. The particles may be conveyed along the identifier,affinity modifier and the separator with a velocity that may range inbetween 0.5-8 m/s, preferably 1-3 m/s and more preferably of about 2.5m/s.

The identifier may be a sensor, e.g. optical sensor and/or an imageprocessing device, e.g. color camera (RGB) for visual assessment, IRcamera for temperature and shape assessment, near-infrared (NIR) camerafor chemo-spectral and shape assessment (e.g. plastic type), X-raymethods such as X-ray Fluorescence (XRF) for elemental assessment orX-ray transmission for density and shape assessment, or laser inducedbreakdown spectroscopy (LIBS) for elemental assessment. The opticalsensor may for example have a resolution in time of better than 0.5 msand a resolution in space of better than 0.5 mm. Therefore, the opticalsensor may accurately define the position, size and/or shape ofparticles passing by.

The affinity of the identified particles which may be modified by theaffinity modifier may be e.g. the adhesiveness e.g. using water or sprayable adhesive on plastic flakes, electric static charge or magneticbehavior of the identified particles. In particular, the affinitymodifier may modify the affinity of the identified particles by applyingaffinity modifying particles to the identified particles, wherein themodifying particles may be charged particles, e.g. electrons tostatically charge the identified particles.

Preferably, the affinity modifying particles may be material particles,wherein the affinity changing particles may form a coating surface layeronto the identified particles. Additionally or alternatively, theaffinity changing particles may form, at least partially, a coatingsurface layer onto the identified particles, i.e. onto a surface of theidentified particles that is facing the affinity modifier. For example,modifying particles may be discharged from the modifier from above theconveyor such that the modifying particles may adhere onto the surfaceof the particles, forming a sticky, moisturized and/or magnetic coatingsurface.

The affinity modifying particles discharged from the affinity modifiermay be liquid droplets and/or powder particles. The affinity modifiermay comprise jets, e.g. jet printer heads. When the affinity modifierdischarges liquid droplets, this may for example be oil, alcohol, butpreferably water to moisturize the identified particles. The identifiedparticles may then be covered by a water layer of approximately 10-20microns. The liquid droplets on the surface of the identified particlesmay then form a moisture bridge between the identified particles and theseparator while the non-identified particles remain substantially dry.Optionally, it is also possible that the liquid droplets on the surfaceof the identified particles form a moisture bridge between theidentified particles and a second material, e.g. powder particles,wherein the powder particles may be discharged by, for example, anotheraffinity modifier, e.g. powder spray, after the identified particleshave been moisturized.

The affinity modifier is arranged for individual engagement ofparticles. The affinity modifier may deliver 50000 droplets per secondper valve, wherein each droplet may have a diameter smaller than 100micron and preferably 40 micron. The valves may be spaced from eachother with a distance of about 0.05 mm or more. In particular, thevalves are preferably arranged for providing droplets at a resolution of100 droplets per inch—or 39 to 40 droplets per centimetre.

It is noted that multiple modifiers or one modifier having multiplevalves may be arranged in a row that is transverse to the conveyordirection, or they may be partly co-moving in the direction of theconveyor to eliminate the relatively motion between the modifier andparticles during the modifying action (e.g, spraying jets mounted on adevice rotating opposite to the conveyor belt). Each valve and/ormodifier may contain different modifying particles to be discharged. Byhaving the modifier that is able to deliver 50000 droplets per secondper valve, it may be achieved that the accuracy between the sensor andthe separator may be better coordinated. In particular, the resolutionof the separator may be about 0.4 mm and thus it easily matches theresolution of the identifier of 0.5 mm and therefore the separator mayoperate with the same accuracy as the identifier.

It is noted that besides the above mentioned fluids, it is also possiblethat the modifier discharges glutinously fluids onto the identifiedparticles, e.g. starch.

The powder particles may be a magnetic powder, e.g. industrialFerrosilicon, preferably spherically shaped. Preferably, the modifierdischarges powder particles after the particles have been at leastpartially covered by liquid droplets. For example, 40-150 micronmagnetic powder particles may be added per moisturized identifiedparticles such that the powder will stick onto the moisturizedidentified particles.

Preferably, the affinity modifier comprises a printer head wherein theprinter head may be of the type inkjet printer for discharging theliquid droplets. The affinity modifier may further comprise a powderspray arranged to discharge the powder particles, e.g. Ferrosilicon.Thus, the printer head is arranged to discharge water droplets onto theidentified particles after which the powder spray sprays sphericallyshaped Ferrosilicon on the moisturized identified particles. Thedroplets may thus form a water bond, with a strength comparable with ayellow sticky note, between the identified particles and theFerrosilicon. By providing the identified particles with liquid dropletsand a layer of Ferrosilicon, the identified particles may be selectivelyattracted to a magnet or a magnetizable material.

The separator may have a contact surface onto which the identifiedparticles are affixed thereon. The separator may be arranged toindividually engage the particles. The separator may be an activeseparator i.e. a separator that is mechanically driven to ensure thatthe contact surface engages the identified particles and/or the group ofparticles. However, it is also possible to have a passive separator,i.e. wherein the identified particles and/or group of particles fallonto the contact surface of the separator. The contact surface may becoated with a hydrophilic material arranged to attract the moisturizedparticles. The contact surface may also be a magnet or at least iscoated with a magnetizable layer arranged to interact with the magneticspherically powder particles that may be on the surface of theidentified particles such that the identified particles may be attractedby the separator, or affix onto it. An advantage of a separator having acontact surface onto which the identified particles are affixed, inparticular with the surface coated with a hydrophilic material and/orthe separator having magnetic properties, is that no pressing of theseparator on the identified particles is required for adherence of theparticles to the separator. This enables short processing times. And inparticular in the case of affixing by means of magnetic attraction, anadditional advantage is that particles other than identified particlesare not in contact with the separator, which reduces the odds ofnon-identified particles 6 to be picked up by the separator.

Preferably, the separator may be a mechanical pick up device having acontact surface that contacts the group of particles for picking up theidentified particles. The separator may, for example, be a drum with arotating axis transverse to the conveyor direction. The drum may have acontact surface that is coated with a magnetizable layer or withhydrophilic fibrous material with fibers having a size that may range inbetween 100-500 micron diameter and is preferably about 300 microndiameter. The fibers may have a rounded top and these fibers may bemoved up and down individually fast enough to connect to moisturizedparticles such that the moisturized particles are affixed onto thefibers.

The invention further relates to a use of a printer head for separationof identified particles from a group of particles.

The invention further relates to a method for separation of particlesfrom a group of particles, comprising the steps of:

-   -   supplying an group of particles in an arrangement, wherein the        group of particles comprises particles with different        properties, e.g. material, color, shape and/or size;    -   identify particles in the group of particles that have a        specific property;    -   modify an affinity of the identified particles relative to that        affinity of non-identified particles in the group with an        affinity modifier;    -   separate the particles in the group based on their difference in        the affinity with a separator.

When fine powder particles, e.g. ferrosilicon have been applied by themodifier to the identified particles, the method may further comprise arecovering step after the separation step, wherein the wetted particleswith ferrosilicon powder on their surface are dried and/or brought intoa magnetic field with a sufficiently high gradient to separate themagnetic powder from the surface of the identified particles such thatferrosilicon powder particles may be recovered.

It is noted that in the method for separation, the identifier may alsobe a human that identifies the particles to be separated and marks themwith a marker.

The invention will be further elucidated on the basis of an exemplaryembodiment which is represented in a drawing. In the drawings:

FIG. 1 shows a first schematic view of the separation apparatus.

FIG. 2 shows a second schematic view of the separation apparatus.

It is noted that the figures are merely schematic representations of apreferred embodiment of the invention, which is given here by way ofnon-limiting exemplary embodiment. In the description, the same orsimilar part and elements have the same or similar reference signs.

In FIG. 1 is shown a separation apparatus 1 comprising an identifier 2arranged to identify the particles 3 in a group of particles 4 that havea specific property. FIG. 2 shows the separation apparatus 1 comprisingoptional further elements.

The separation apparatus 1 is arranged for individual engagement ofparticles. The particles may be small particles such as shredded PE, PPor PET of different colors or different grades with a diameter size thatmay range between 1-20 mm. An affinity modifier 5 is provided that isarranged to selectively modify an affinity of the identified particles 3relative to that affinity of non-identified particles 6 in a group 4,and a separator 7 is arranged to separate the particles in the group 4based on their difference in the affinity. The specific property that ismeasured by the identifier 2 may be, e.g. a type of material, weight,color, shape and/or size.

The sensor separation apparatus 1 in the example further comprise alayerizer 8 arranged to bring the group of particles 4 in layer, andpreferably provides the particles 4 in the layer with a known constantspatial relation in the layer between the identifier 2 and the affinitymodifier 5. Worded differently, the particles 4 are by the layerizer 8provided such that the travel time from the identifier 2 and theaffinity modifier 5 is known. This allows operation of the identifier 2and the affinity modifier 5 to be synchronized.

The layerizer 8 in this embodiment comprises a conveyor belt surface 8Aon which the particles are deposited in a planar layer. The conveyorbelt surface 8A preferably has a high-friction surface, for examplecomprising synthetic and/or natural rubber. As shown in FIG. 1 the groupparticles 4 are being fed onto the conveyor belt surface 8A by a feeder9. The group particles 4 may be fed onto the conveyor belt as acontinuous curtain of particles or as sections with a predetermineddistance. Optionally, the group particles 4 first passes magnetic scrapremover 15 for removing particles in the particle feed having magneticproperties. The magnetic scrap remover may comprise a magnet 20 forattracting particles having magnetic properties, like particlescomprising ferromagnetic metal. Particles comprising ferromagnetic metalmay comprise such ferromagnetic metal in a pure form or in a compound,like a salt or other.

The identifier 2 is in FIG. 1 embodied as an optical sensor 10 whereinit is positioned above the layerizer 7 to identify the group particles 4that have a specific property. For example, the identifier 2 is arrangedto identify the color of the particles 4 in a stream of clear and inparticular translucent particles. The identifier 2 is also arranged toidentify a specific type of PP via a marker provided in the PP material.Furthermore, the identifier 2 is arranged to identify the position ofthe particles on the conveyor belt surface 8A.

After the particles 4 have passed along the identifier 2, the affinitymodifier 5 modifies the affinity of the identified particles 3 byapplying affinity modifying particles 11 to the identified particles 3.The modifying particles 11 is, for example discharged from above theconveyor belt surface 8A such that the affinity modifying particles 11form a coating surface layer onto the identified particles 3. Theaffinity modifying particles 11 are preferably discharged with acomponent of their velocity parallel to the motion of the conveyor beltsurface 8A. In this way, it may be avoided that identified particles 3are missed by the particles by time of flight effects related tovariations in the height of the identified particles above the conveyorbelt surface 8A.

The affinity modifying particles 11 may in FIG. 1 be liquid dropletsand/or powder particles wherein the liquid droplets is in this exampleis water to moisturize the identified particles to form a moisturebridge between the identified particles 3 and the separator 7. The watermay be provided with a minor amount of additives to improve theelectrical conductivity. A reason for this is that some printers requirethe liquid to be disposed to have a certain electrical conductivity forproperly discharging the liquid. This applies not only to ink, but alsoto water in case water is to be discharged by the printer. Optionally,it also possible that after the identified particles 3 have beenmoisturized by liquid droplets, a second modifier 5B or the samemodifier 5A discharges a second material, preferably powder particles.The powder particles in FIG. 1 may be magnetic powder particles, e.g.industrial ferrosilicon wherein they are preferably spherically shapedsuch that the identified particles 3 may be engaged individually and/orlifted by the separator 7.

Typically, more than one ferrosilicon particle is discharged peridentified particle 3. Preferably, a significant amount of ferrosiliconparticles is discharged per identified particle 3. In particular, theamount of ferrosilicon particles to be discharged is at least 1% andpreferably more than 4% of the mass of an identified particle 3. Forpreventing any powder particles freely moving over the conveyor beltsurface 8A, the conveyor belt surface 8A may comprise grooves orientedsubstantially perpendicular to a direction of movement of the conveyorbelt surface 8A. Preferably, the grooves are less than one millimeter.Preferably, the particles are discharged with a speed componentperpendicular to the conveyor belt surface 8A of less than 1 m/s. Inaddition, a speed component parallel to the conveyor belt surface 8A istuned to the velocity of the belt surface 8A.

The affinity modifier 5 is in FIG. 1 embodied as a printer head 5Aand/or a powder spray, e.g. Ferrosilicon spray 5B. With the affinitymodifier 5 comprising a printer head 5 A for distributing water oranother liquid for moisturizing the liquid droplets, the printer head 5A is arranged for providing droplets smaller than 100 micron, preferably30 to 50 micron. The droplets are preferably provided at a resolution ofat least 100 droplets per inch—or 39 to 40 droplets per centimetre. Atthis resolution, it is possible to deposit liquid only on identifiedparticles 3. Additionally to this, powder particles may be discharged oneither identified particles 3 only or on all particles. On identifiedparticles 3, powder particles are bound by the liquid on the identifiedparticles 3. Powder particles on other particles 6 may be removed, forexample by means of blowing or a magnetic field. Alternatively, in anembodiment in which liquid as well as powder particles are discharged,liquid is deposited at all particles 4 on the conveyor belt and thepowder particles are only discharged on the identified particles 3.

If identified particles are moisturized, this may be done in a blanketfashion, deploying a blanket or substantially continuous film of liquidon either all particles 4 or identified particles 3. Alternatively,liquid is discharged on specific areas. This may for example beestablished by depositing the liquid in lines. These lines may beparallel to the motion of the conveyor belt, perpendicular to the motionof the conveyor belt or under an angle relative to the motion of theconveyor belt.

In certain embodiments, it may be desired to pretreat the particles 4for improving adherence between affinity modifying particles and thegroup particles 4. To this purpose, a pre-treatment module 21 (FIG. 2)is provided for pretreating the group particles 4. If the affinitymodifying particles comprise water, it may be preferred to improvehydrophilic properties of the group particles 4. In one specificembodiment, a very thin layer (1 to 10 nanometers) of calcium carbonateis applied to the group particles. Such layer of calcium carbonate maybe applied by exposing the group particles to water having asufficiently high hardness (measured, for example, in German degrees) ata temperature of at least 80 degrees centigrade. Exposure may beprovided by means of spraying or submersion. Submersion is preferablydone for at least 30 seconds, in water of sufficient hardness, at atemperature of at least 80 degrees. Alternatively or additionally, acoating of for example hexamethyldisilazane and/or other hydrophobicsubstances may be provided as a coating for the group particles 4. Thehydrophilic coating may be applied on all particles or on identifiedparticles 3 only.

In a region around the ferrosilicon spray 5B—or other discharge unit fordischarging particles having magnetic properties—a weak magnetic fieldmay be applied. The field lines of the magnetic field are providedsubstantially parallel to the direction of movement of the layerizer 8and the conveyor belt surface 8A in particular. The intensity of themagnetic field preferably ranges from 0.01 Tesla to 0.05 Tesla. As aneffect of the magnetic field, rolling of the powder particles on theconveyor belt surface 8A as a result of damping by magnetic hysteresisis suppressed. This is because the magnetization of a rolling particlein a unidirectional field creates a loss of mechanical energy into heat.Furthermore, the applied weak magnetic field also has the effect todeposit the powder particles onto the wetted particles arranged in shortstrings for example, three powder particles in a row. This is favorablefor the later magnetic extraction of the scrap particles and allows areduced use of magnetic powder.

The separator 7 has a contact surface 12 onto which identified particles3 are affixed thereon such that they can be separated from the groupparticles 4. The separator 7 individually engages particles forseparation. Preferably, the separator 7 is a mechanical pick up devicewhich contact surface 12 contacts the group of particles 4 for pickingup the identified particles 3. As shown in FIG. 1 the separator 7 isembodied as a drum 13 having a rotating surface transverse to theconveying direction. Worded differently, the axis of rotation of thedrum 13 is perpendicular to the conveying direction. The contact surface12 of the drum 13 is in this example coated with a hydrophilic fibrousmaterial such that the identified moisturized particles may be affixedthereon.

Further, it is also possible that the separator 7 is a magnet or thatits contact surface 12 is a magnet, has magnetic properties, or at leastis coated with a magnetizable layer to separate the identified particles3 which have been coated with magnetic powder. In addition, if theseparator 7 is a magnet or its contact surface 12 is a magnet, or atleast is coated with a magnetizable layer, the separator may be used torecover particles having magnetic properties that may have beendischarged upstream of the conveyor belt surface 8A. This may beparticles that are adhered to identified particles 3 and/or particlesnot adhered to identified particles 3, but present on the conveyor beltsurface 8A and/or present on non-identified particles 6 not having beenprovided with liquid. The particles thus recovered are fed back to areservoir 17 (FIG. 2), allowing for reuse of the particles. Beforereuse, the particles may be de-magnetized by means of a de-magnetizer 18(FIG. 2) and/or dried, for example in a fluidized bed 19 (FIG. 2). It isnoted in other embodiments, the order of the reservoir 17, thede-magnetizer 18 and the fluidized bed 19 may be different.

Further, in FIG. 1 and FIG. 2 is shown that a second conveyor 14 may beprovided to convey the identified particles 3 away from the groupparticles 4 after the identified particles 3 have been separated.

As for the purpose of this disclosure, it is pointed out that technicalfeatures which have been described may be susceptible of functionalgeneralization. It is further pointed out that—insofar as not explicitlymentioned—such technical features can be considered separately from thecontext of the given exemplary embodiment, and can further be consideredseparately from the technical features with which they cooperate in thecontext of the example.

It is pointed out that the invention is not limited to the exemplaryembodiments represented here, and that many variations are possible. Forexample, the identifier may also be an identifier station comprisingmultiple identifiers arranged in a row or the separation apparatus maycomprise multiple identifiers stations, preferably also arranged in arow. There may also be an affinity modifier station or a separatorstation.

Further, it is noted that the separator and the affinity modifier may beaccommodated in a single device wherein modifying the affinity ofidentified particles and separation may be single action and may takeplace at the same time at a same position.

It is further noted that multiple separation apparatus may be placed inone go, e.g. above a conveyor, such that multiple different particlesmay be separated from a single stream of particles.

These and other embodiments will be apparent to the person skilled inthe art and are considered to lie within the scope of the invention asformulated by the following claims

The invention claimed is:
 1. A separation apparatus, comprising: anidentifier arranged to identify the particles in a group of particlesthat have a specific property; an affinity modifier arranged to modifyan affinity of the identified particles relative to that affinity ofnon-identified particles in an group; a separator arranged to separatethe particles in the group based on their difference in the affinity;wherein: the affinity modifier modifies the affinity of the identifiedparticles by applying affinity modifying particles to the identifiedparticles; and the affinity modifying particles comprise liquid dropletsto moisturize the identified particles to form a moisture bridge betweenthe identified particles and the separator.
 2. The apparatus accordingto claim 1, further comprising a layerizer arranged to bring the groupof particles in layer.
 3. The apparatus according to claim 2, whereinthe layerizer provides the particles in the layer with a known,preferably constant, spatial relation in the layer between theidentifier and the affinity modifier.
 4. The apparatus according toclaim 2, wherein the layerizer comprises a conveyor belt surface onwhich the particles are deposited in a planar layer.
 5. The apparatusaccording to claim 1, wherein the identifier is an optical sensor. 6.The apparatus according claim 1, wherein the affinity modifyingparticles form a coating surface layer onto the identified particles. 7.The apparatus according to claim 1, wherein the affinity modifyingparticles further comprise powder particles.
 8. The apparatus accordingto claim 7, wherein the powder particles comprise magnetic powderparticles that are spherically shaped.
 9. The apparatus according toclaim 1, wherein the affinity modifier comprises a printer head.
 10. Theapparatus according to claim 1, wherein the specific property is a typeof material, color, shape and/or size.
 11. The apparatus according toclaim 1, wherein the separator has a contact surface onto whichidentified particles are affixed thereon.
 12. The apparatus according toclaim 11, wherein the contact surface is coated with hydrophilic fibrousmaterial.
 13. The apparatus according to claim 11, wherein the contactsurface comprises a magnet or at least is coated with a magnetizablelayer.
 14. The apparatus according to claim 1, wherein the separatorcomprises a mechanical pick up device having a contact surface thatcontacts the group of particles for picking up the identified particles.15. The apparatus according to claim 1, wherein the separator comprisesa drum.
 16. The apparatus according to claim 1, wherein the group ofparticles comprises small particles with a diameter size of 1-20 mm. 17.The apparatus according to claim 1, wherein the affinity modifyingparticles comprise water droplets.
 18. A method for separation ofparticles from a group of particles, comprising the steps of: supplyingan group of particles in an arrangement, wherein the group of particlescomprises particles with different properties, the different propertiescomprising one or more of: material, color, shape and size; identifyparticles in the group of particles that have a specific property;modify an affinity of the identified particles relative to that affinityof non-identified particles in the group with an affinity modifier;separate the particles in the group based on their difference in theaffinity with a separator; wherein: the affinity modifier modifies theaffinity of the identified particles by applying affinity modifyingparticles to the identified particles; and the affinity modifyingparticles comprise liquid droplets to moisturize the identifiedparticles to form a moisture bridge between the identified particles andthe separator.
 19. The apparatus according to claim 8, wherein thepowder particles comprise industrial ferrosilicon.